In recent weeks, the volatility of the US stock market has significantly increased, and traders are increasingly concerned about any signs that indicate the US economy is cooling faster than expected. The S&P 500 index has fallen by about 3% from its peak in late August.

Rebecca Cheong, Chief Equity Derivatives Strategist at UBS AG, stated that she expects the S&P 500 index to fall at least 10% from its peak within the next month.

Rebecca Cheong wrote in a report to clients on Tuesday: "I am tactically bearish on the US stock market for the next two months, and even any slight disappointment in the upcoming economic data could trigger a sharp decline."

She recommends investors to buy tail hedge funds to prevent losses, and lists iShares Russell 2000 ETF (IWM), SPDR Financial Select Sector ETF (XLF US), and iShares iBoxx High Yield Corporate Bond ETF (HYG) as preferred options.

Cheong added that while her views reflect a growing pessimism in the market, it is not a long-term view. "If there are no news events, the market may just continue to see moderate selling," she added.

Other strategists also have a cautious short-term stance, such as Christian Mueller-Glissmann of Goldman Sachs. In a report on September 9th, he stated that the risk-adjusted returns of stocks will decline by the end of the year, but it is unlikely that the S&P 500 index will enter a bear market.

He said that it is unlikely for the U.S. stocks to plummet by 20% or more, because the risk of an economic recession is still low and the Federal Reserve is expected to cut interest rates.

The team, led by him, stated that although the stock market may experience more pullback risks before the end of the year due to rising valuations, mixed growth prospects, and policy uncertainties, the possibility of entering a bear market is small because the economy is also supported by the "healthy growth of the private sector" to a certain extent.

In addition, historical analysis by the strategist shows that the frequency of the S&P 500 index falling more than 20% since the 1990s has decreased, driven by longer business cycles, lower macroeconomic volatility, and the "buffer" effect of central bank policies.

In the report, they stated that they maintain a tactically neutral asset allocation, but "moderately support risk-taking" within a 12-month timeframe.

Furthermore, data from Citigroup indicates a "bearish bias", suggesting that major U.S. stock indices are prone to further short-term declines.